Metal insulator transition and magnetotransport anomalies in perovskite SrIr0.5Ru0.5O3 thin films

Abstract

We investigated the nature of transport and magnetic properties in SrIr0.5Ru0.5O3 (SIRO), which has characteristics intermediate between a correlated non-Fermi liquid state and an itinerant Fermi liquid state, by growing perovskite thin films on various substrates (e.g., SrTiO3 (001), (LaAlO3)(0.3)(Sr2TaAlO6)(0.7) (001), and LaAlO3 (001)). We observed systematic variation of underlying substrate dependent metal-to-insulator transition temperatures (T-MIT similar to 80K on SrTiO3, similar to 90 K on (LaAlO3)(0.3)(Sr2TaAlO6)(0.7), and similar to 100K on LaAlO3) in resistivity. At temperature 300K >= T >= T-MIT, SIRO is metallic and its resistivity follows a T-3/2 power law, whereas insulating nature at T < TMIT is due to the localization effect. Magnetoresistance (MR) measurement of SIRO on SrTiO3 (001) shows negative MR at T < 25K and positive MR at T > 25 K, with negative MR proportional to B-1/2 and positive MR proportional to B-2; consistent with the localized-to-normal transport crossover dynamics. Furthermore, observed spin glass like behavior of SIRO on SrTiO3 (001) at T < 25 K in the localized regime validates the hypothesis that (Anderson) localization favors glassy ordering. These remarkable features provide a promising approach for future applications and of fundamental interest in oxide thin films. (C) 2015 AIP Publishing LLC.